I mpwbvjemen f in crank-connections fgr steawl-engines



1. ILMcGdWA & n. B. CALDWELL.

Crank-Connections for Steam Engines. NC- ]43,292. Patented September30,1873.

dent that the engine is automatically carried beyond the dead-points without consuming live steam or detracting from the power of the motor.

The auxiliary cylinder R has no communication whatever with the external atmosphere, but is simply filled from chest 0 with a supply of live steam, which returns to said chest as soon as the engine has been assisted over the dead-points.

It is evident that the same results can be produced by supplying the auxiliary cylinder with live steam direct from the boiler; but such an arrangement would not be as compact and simple as the form shown in the illustration.

The engine may be modified, as shown in Fig. 4, in which arrangement the bell-crank is omitted, and an arm, X, is substituted therefor, which arm vibrates upon a stud, Y. Z is a link, which connects said arm X with the crank K upon the fly-wheel shaft. With these exceptions the engine is essentially the same as that shown in the preceding illustration.

It will be seen that either the preferred arrangement shown in Figs. 1, 2, and 3, or the modification represented in Fig. 4., enables us to dispense with the gearing employed in the engine described in the patent previously alluded to, and consequently the noise and back- 12.8% incidental to cog-gearing is entirely obviate It will be perceived that a fly-wheel is not absolutely essential to the operation of our engine. In practice, however, we prefer to use a light fly-wheel, in order to secure uniform motion and for an additional safeguard.

It will be perceived that the auxiliary cylinder or chamber does not exhaust steam, but simply receives the pressure of the steam on its passage from the boiler to the main cylinder; and we thus utilize the pressure, before it is consumed by the engine, to overcome the dead-points without expenditure of steam.

It will also be understood that the engine, as shown, is simply the ordinary reciprocating slide-valve engine, and to which our improvement is adapted; and that the pressure and power of the auxiliary preserves an automatic relation to that of the engine, so as, without care, attention, or adjustment of any kind, to

overcome any increasing resistance at the dead-points consequent on additional work, and the opening of the throttle by the governor to meet the same.

We claim as new and of our invention- In combination with the driving-shaft I W of a steam-engine, the crank K, bell-crank L l l, connecting-rod M, coupling-rod N, and piston P of the auxiliary cylinder R T, when arranged and adapted to operate substantially as herein described and illustrated.

In testimony of which invention we hereunto set our hands.

JOHN H. MOGOWAN. DAVID B. CALDWELL.

Attest:

GEO. H. KNIGHT, JAMES H. LAYMAN. 

